Wound infections have gradually become a major threat to human health. Recently, covalent organic frameworks (COFs) have shown great potential in antibacterial and wound healing; however, difficult biodegradability and long-time in vivo retention limit their further application. Herein, biodegradable COFs containing porphyrin backbones and hypoxia-sensitive azobenzene group, namely, HRCOFs, are fabricated for photodynamic therapy (PDT) and photothermal therapy (PTT) of wound infection. Due to the introduction of a porphyrin molecule, HRCOFs can produce singlet oxygen (¹O₂) under 660 nm laser irradiation. The prepared HRCOFs can also generate thermal energy under 808 nm NIR laser irradiation. HRCOFs show excellent synergetic antibacterial ability against Staphylococcus aureus (S. aureus) andEscherichia coli(E. coli) in vitro. The in vivo experiments also demonstrate synergistic PDT and PTT effects of HRCOFs against wound infection. Importantly, HRCOFs are response to wound microenvironment, can be degraded for clearance, and avoid some adverse effects caused by long-time retention in vivo, exhibiting good biocompatibility. In general, the obtained biodegradable HRCOFs with both photodynamic and photothermal effects can be used for antibacterial infections and provide great value for promoting wound healing.

中文翻译：

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缺氧活化的可生物降解卟啉共价有机框架用于伤口感染的光动力和光热疗法


伤口感染已逐渐成为对人类健康的主要威胁。最近，共价有机框架 （COF） 在抗菌和伤口愈合方面显示出巨大的潜力;然而，难以生物降解和长时间的体内保留限制了它们的进一步应用。在此，制备了含有卟啉骨架和缺氧敏感偶氮苯基团的可生物降解 COFs，即 HRCOFs，用于伤口感染的光动力疗法 （PDT） 和光热疗法 （PTT）。由于引入了卟啉分子，HRCOFs 可以在 660 nm 激光照射下产生单线态氧 （¹O₂）。所制备的 HRCOFS 还可以在 808 nm NIR 激光照射下产生热能。HRCOFs 在体外对金黄色葡萄球菌 （S. aureus） 和大肠杆菌 （E. coli） 表现出优异的协同抗菌能力。体内实验还证明了 HRCOFs 对伤口感染的协同 PDT 和 PTT 作用。重要的是，HRCOFs 是对伤口微环境的反应，可以降解以进行清除，并避免了长时间保留在体内引起的一些不利影响，表现出良好的生物相容性。一般来说，获得的具有光动力和光热效应的可生物降解 HRCOFs 可用于抗菌感染，为促进伤口愈合提供巨大价值。